POSITIVE SELECTION SYSTEM FOR STABILISATION OF EXPRESSION VECTORS

摘要

The invention relates to a method for the construction of plasmids assuring the insertion of a nucleotide sequence into a chromosome and the simple separation of clones containing the transformed chromosome by using methods of genetic engineering known per se which comprises inserting a copy of a chromosomal segment corresponding to a chromosomal segment of the host cell between the transcription regulating sequences capable of expressing foreign gene into a plasmid containing transcription regulating sequences capable of expressing foreign gene and a resistance gene (R2) expressed independently from the said regulating sequences, then downstream inserting a resistance gene without own promoter (R1) different from (R2), and finally inserting a sequence containing at least one transcription terminator into the inserted copy of the chromosomal segment.